FIG. 1 is a structural diagram of a traditional cellular wireless communication system. As shown in FIG. 1, the cellular wireless communication system mainly includes a Core Network (CN), a Radio Access Network (RAN) and a terminal. The CN is responsible for a transaction for a non-access stratum, such as terminal position update, and is an anchor point for a user plane. The RAN includes base stations, or the base stations and a base station controller. The RAN is responsible for a transaction for an access stratum (such as management of radio resources). There may be physical or logical connections between the base stations according to a practical situation, e.g., the connection between a base station 1 and a base station 2 and the connection between the base station 1 and a base station 3 as shown in FIG. 1. In addition, each base station may be connected to one or more CN nodes. The terminal refers to a User Equipment (UE), and is one of various devices that may communicate with a cellular wireless communication network, e.g., a mobile phone or a laptop.
A Machine Type Communication (MTC) service refers to a service used for communication between machines. In the MTC service, there is no need of human participation and all communication is completed by machines independently. A machine terminal obtains data through a sensing device including a sensor, then reports the data to a mobile communication network through the communication module of the machine terminal and accesses a public data network via the mobile communication network. The MTC service may include applications such as logistics monitoring, safety monitoring, remote medical detection and remote meter reading. Data of the MTC service may be managed by a mobile communication operator or a specific server of a special MTC operator, and may be checked by an MTC subscriber or an MTC manager. In this process, a device which obtains data required for the service is a terminal.
A characteristic different from traditional mobile communication technology is introduced into the MTC service, e.g., the group-based MTC characteristic. When the group-based MTC characteristic is activated, a network can control, manage or charge an MTC terminal group according to requirements of an operator. In this way, the group-based MTC characteristic provides a simpler mode for controlling/updating/charging MTC terminals by taking groups as granularities, and reduces redundant signalings to avoid network congestion. When there are a large number of MTC terminals, the group-based MTC characteristic can further save network resources. All terminals in a group may be in the same region, and/or be provided with the same MTC properties and attributes, and/or belong to the same MTC subscriber. With regard to a network, all terminals in the group are visible.
For the group-based MTC characteristic, when an MTC subscriber subscribes a terminal group, the operator needs to set and activate the group characteristic in subscription information of all terminals in the group, and stores the set subscription information of all terminals into a Home Subscription Server (HSS). Here, the HSS is an entity which is responsible for storing identity information, authentication information, authorization information and the like of a user or a terminal in a telecom network. According to different conditions, the HSS may be configured to store the identity information of the user and binding information of the user and the terminal, or may only store the identity information of the user, or may only store the identity information of the terminal. Here, the binding information of the user and the terminal may be stored by a Gateway (GW) when the HSS only stores the identity information of the user. In addition, the HSS is further responsible for a subscription database of a user, user identity authentication and authorization and the like. A service platform may inquire subscription information of the user or the terminal device from the HSS.
When a terminal is attached to a network, a Mobility Management Entity (MME) acquires the subscription information of the terminal from the HSS and stores the subscription information locally. The MME is an entity for managing control signalings of terminals in a CN, and is responsible for access control. The access control includes authentication control, identity assignment, user identity and device identity authentication, encryption for a signaling plane, protection of consistency with an Evolved Node B (eNB), conversion of safety parameters and Quality of Service (QoS) parameters between 2G/3G and Evolved Packet Systems (EPSs), access permission control, determination of whether to be able to acquire and reserve requested resources, legal interception, mobility management, session management, related operations for EPS bearers, network element selection and the like. The identity assignment refers to assignment of Globally Unique Temporary Identity (GUTI), Tracking Area Identity (TAI) list and the like. The mobility management may specifically refer to implementation of tracking and recording of the current location of a UE and the like.
In existing technologies, a terminal reachability notification request procedure (UE Reachability Notification Request Procedure) and a terminal activity notification procedure (UE Activity Notification Procedure) are defined in a terminal reachability procedure (UE Reachability Procedure), so as to implement network management for terminal reachability, namely, the reachability of a terminal may be acquired by any service-related entity in a network.
However, existing network functions fail to control the terminal reachability procedure of a terminal group according to subscribed group information after the group-based MTC characteristic is introduced, such that network congestion may be caused when the reachability of a large number of MTC terminals in the terminal group are acquired simultaneously by any service-related entity.